Flexible acoustic tube



Nov. 29, 1949 R. A. FARALLA FLEXIBLE ACOUSTIC TUBE Filed Sept. 12, 1945 INVENTOR.

RAOUL A. FARALLA ATTORNEY Patented Nov. 29, 1949 UNITED STATES PATENT OFFICE FLEXIBLE ACOUSTIC TUBE Raoul A. Faralla, Long Branch, N. J., assignor to the United States of America as represented by the Secretary of War (Granted under the act of March 3, 1883, as amended April 30, 1928; 370 0. G. 757) 2 Claims.

The invention described herein may be manufactured and used by or for the Government for governmental purposes, without the payment to me of any royalty thereon.

The present invention relates to hearing devices and particularly to resilient members adapted to be inserted in the ears for conducting sound thereto. Telephone headsets and other apparatus for conveying sound to a persons ears have been faulty because circumambient noises are not shut out. Efiorts to correct this shortcoming have resulted in various types of equipment which are provided with soft tubular elements directed into the ear and forming an acoustic seal therewith. As a result of variations in the geometry of the ear canals and the ear structures of different persons and the movements of the hearing apparatus while in use, said tubular elements are necessarily subjected to longitudinal and lateral deformations, which sometimes adversel affect their acoustic characteristics, and sometimes even cause them to be so constricted as to completely prevent the passage therethrough of any sound at all.

It is, therefore, an object of the present invention to provide an ear insert which is flexible both longitudinally and laterally, which does not unfavorabl affect the passage of sound therethrough, and which does not close up so as to completely out off the passage of sound and which, nevertheless, is comfortable for the wearer.

In general, the present invention comprises a tubular member made of soft resilient material, such as a soft compound of natural or synthetic rubber, and which is made of folds or corrugations throughout part of its length so as to allow longitudinal and/ or lateral deformations thereof, and wherein the material at the outer folds is relatively thin and at the inner folds is relatively thick.

For a better understanding of the invention, together with other and further objects thereof, reference is had to the following description taken in connection with the accompanying drawings, and its scope will be pointed out in the accompanying claims.

In the drawings,

Figure 1 is a composite view, partly in elevation and partly in longitudinal section, of an ear insert embodying the present invention, in its normal undeformed state;

Figure 2 is a longitudinal sectional view of the insert of Figure 1, attached to part of an earphone, and shown deflected laterally; and

Figure 3 is a view, similar to Figure 2, wherein the insert is shown when shortened longitudinally.

The embodiment of the present invention shown in the drawings, comprises an ear insert of soft, highly resilient rubber-like material, which at its inner end is provided with an undercut cavity I l for attachment to an earphone [3 or the like, and which at its outer end is provided with a mushroom-like flange l5, adapted to seal against the outer end of one of the wearers ear canals. The central .portion of the insert is formed with folds or corrugations, the material of which is so arranged that, at the inner folds II, the material is relatively thick and, at the outer folds IS, the material is relatively thin. The tubular member forms an axial acoustic passage 2|.

In the use of the device just described, it will be noted, as shown in the drawings, that irrespective of any deformations which may occur in actual use, the thickened inner folds I9 will remain substantially undeformed, while the relatively thin outer folds l9 will collapse as necessary to allow the insert to conform to the deflections sustained by it. This is particularly well illustrated in Figure 3 where, despite considerable longitudinal shortening, the inner folds I1 have flattened out very little, whereas the outer folds [9 have flattened out considerably. The result is that there is no appreciable inward buckling of the material at the inner folds I! which might completely close the acoustic passage 2|, or might at least so distort it as to seriously upset the acoustic characteristics of the device and perhaps result in the conveyance of unintelligible sounds.

Although a specific embodiment of the present invention has been described herein, it will be understood that various modifications may be evident to those skilled in the art.

What is claimed is:

1. A tube for an acoustic device, comprising a corrugated tubular portion of resilient material having a plurality of inner and outer folds disposed about the axis of said tubular portion, each inner fold being relatively thick and, in lateral cross section, having a substantially uniform radial dimension, and each outer fold being relatively thin and in lateral cross section, having a substantially uniform radial dimension, so that, upon deflection of said portion, substantially no distortion occurs at the inner folds, whereby a central acoustic passage is defined by said inner folds irrespective of deformations of said portion.

2. A tube for an acoustic device comprising a corrugated tubular portion of soft resilient material, said portion including a plurality of annular segments disposed coaxial with, and normal to, the axis of said portion, at least one of said segments including a relatively thick annular inner :fold which is relatively resistant to deformation and which defines an axial acoustic passage during operation, at least another of said segments including a relatively thin and readily deformable annular outer fold, said inner fold and outer fold segments being arranged alternately, whereby,

Number upon deformations of said portion, the inner fold 10 segments remain substantially undeformed so as to maintain a substantially undistorted acoustic passage.

RAOUL A. FARALLA.

REFERENCES CITED The following references are of record in the file of this patent:

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